The invention relates to a continuously operating centrifugal separator for separating liquid mixtures, which has paring means for the continuous discharge of the separated liquid phases, an air seal plate being provided above the upper paring means, the air seal plate being fixedly joined to the paring means and extending into a liquid barrier revolving with the centrifuge drum, and one or more radially disposed overflow passages being provided in the centrifuge drum between the lower and upper paring means.
Such centrifugal separators are known, in which the air seal plate extending into a liquid barrier and disposed above the upper paring means prevents the entry of atmospheric air into the upper paring chamber and hence the entry thereof into the liquid discharged from this chamber by the paring means.
The liquid barrier required for the sealing of the air seal plate can consist of a foreign liquid or a portion of the liquid being removed by the upper paring means.
The overflow passages radially disposed between the two paring means serve for the purpose of removing from the drum liquids overflowing from the upper and/or lower paring chambers, so as to prevent any mingling of the two phases in either of the paring chambers due to overflow.
In the case of liquids which are sensitive to air and which must be kept germ-free, these overflow passages disposed between the paring chambers and connected to the outer drum chamber have proven to be a drawback, since atmospheric air can be drawn through these open passages into the centrifuge drum and can thus enter into the liquid, and in many products this can result in infections which it is essential to avoid.